T1 L18: Plasticity and regeneration

Question 1

What determines gene expression in individual cells?

Answer 1

Inducing factors
-signalling provided by other cells

Competence
-The ability to respond to the factors

Question 2

How does distribution of notch-1 and numb determine cell roles?

Answer 2

Vertical division causes the cells to have both a notch-1 and numb so they will become stem cell

Horizontal division causes cells to have either a notch-1 or a numb. Only notch-1 causes neuroblasts which migrate away. Only numb causes progenitor cells with a limited mitotic potential

Question 3

What is a neuroblast?

Answer 3

An undifferentiated precursors of the central nervous system

Question 4

What determines the fate of the migrating neurone?

Answer 4

• Age of precursor cell
• Position of ventricular zone
• Environment at time of division

Question 5

What is meant by inside-out development of the cortex?

Answer 5

Cells migrate outwards to form each of the layers

Question 6

What is the function of growth cones and filopodia?

Answer 6

Growth cones facilitate axon growth and guidance by bundling and extending actin filaments into structures known as filopodia and microspikes

Question 7

Give an example of a chemoattractant

Answer 7

Netrin

Question 8

Give an example of a chemorepellent

Answer 8

Slit

Question 9

What is the function of chemoattractants and chemorepellents?

Answer 9

They guide growth